Distribution patterns of two species of Corynosoma (Acanthocephala: Polymorphidae) in fishes from Southwestern Atlantic

CANEL, DELFINA; LEVY, EUGENIA; ALARCOS, ANA J.; BRAICOVICH, PAOLA E.; CANTATORE, DELFINA M. P.; IRIGOITIA, MANUEL M.; LANFRANCHI, ANA L.; TIMI, JUAN T.

PARASITOLOGY RESEARCH

SPRINGER

Año: 2019

0932-0113

Corynosoma australe and C. cetaceum are the most frequently reported acanthocephalans in fish from the Argentine Sea, partic-ularly in central and northern areas. Their definitive hosts are otariids and odontocete cetaceans, respectively. The low specificity ofthese larvae, in combination with high infective capability and long survival periods in fish, make them potentially good biologicalmarkers for stocks and other biological features of their fish hosts. In order to determine the distribution patterns of these species andtheir determining factors, a large dataset composed by newly collected fish samples, published and unpublished data from previousstudies by the authors in the region were analysed in relation to host and environmental variables. The complete dataset comprised atotal of 5084 fish, belonging to 29 species distributed in 21 families and 9 orders. Host size and trophic habits arose as the maindeterminants of abundance for both species of Corynosoma, showing higher abundances on larger fish and on higher trophic levels,as it is usual for trophically transmitted parasites. Biogeographic province and depth (indirectly representing the temperature ofwater) were the main drivers of the spatial distribution, displaying a latitudinal pattern associated to the temperature clines created bythe interaction of Malvinas and Brazil currents, determining a decrease in abundance southwards and towards the deeper areas. Nopatterns were found regarding the distribution of definitive hosts. The knowledge of these distribution patterns of Corynosoma spp.in fish at regional scale, as well as of their causes, provides useful information to design management and conservation policies thuscontributing to maintain the full and sustainable productivity of fisheries.